1. Field of the Invention
The present invention relates to a metallically lustrous thermochromic laminate member of various metallic colors such as gold or silver, and a coating composition and a sheet adapted to be used in the preparation of said laminate member.
2. Related Background Art
Thermochromic materials showing reversible color change between a colored state and a colorless state or between a first colored state and a second colored state are already disclosed, for example, in the U.S. Pat. Nos. 4,028,118, 4,720,301 and 4,732,810, and thermochromic members employing such materials have been commercialized in the fields of temperature-indicators, toys, articles for magic etc.
However, there have not been known thermochromic materials that show, by a temperature change, a reversible color change between a metallic luster color such as gold or silver and a colorless state or another colored state, nor thermochromic members that clearly exhibit such color change.
An attempt to diversify the color change is disclosed in the Japanese Utility Model Publication No. 3-14400. The thermochromic member disclosed therein is formed by covering thermosensitive liquid crystal with a pearl luster layer, thereby realizing a color change with pearl luster.
However, since liquid crystal is basically colorless and only reflects a certain wavelength by selective scattering of the visible light, it requires a dark opaque layer in the back and therefore shows color changes of black-red-yellow-green-blue-purple-black. Consequently clear color changes cannot be realized when a pearl luster layer is provided thereon. For example, if a pearl luster gold-color pigment is employed, the colors appear in the order of gold, gold-toned red, gold-toned yellow, gold-toned green, gold-toned blue, gold-toned purple and gold, and there cannot be obtained a clear change to a color without gold tone. Also in case a pearl luster silver-color pigment is employed, the color changes in the order of silver, silvery red, silvery yellow, silvery blue, silvery purple and silver, without clear change to a color free from metallic luster. Also with other metallic luster pigments, the behavior is similar and there cannot be obtained clear change from a metallic luster color to a color without such metallic luster. It is furthermore not possible to achieve a change from the pearl luster color to a colorless state, nor to conceal or display the background color.
Since gold, silver and other metallic luster colors appear gorgeous, a color change from such metallic luster color to another color is most impressive to the spectators and has therefore been longed for in the thermochromic material.